Rock & Mineral Encyclopedia
Search and identify 1,000+ rocks, minerals, crystals, and gemstones — with properties, formation, colors, hardness, and how to tell them apart.
Black Opal
The rarest and most valuable opal, with a dark body tone that makes its flashing rainbow play-of-color blaze brilliantly.
gemstoneSemiblack Opal
Opal with a dark grey body tone sitting between black and light opal, giving play-of-color rich contrast at an accessible price.
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Lightning Ridge Opal
Opal from Lightning Ridge, Australia, the world's premier source of black opal with brilliant color on a dark body.
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Honduran Opal
Precious opal from Honduras occurring in a dark volcanic matrix, where bright flecks of color flash against a natural black basalt background.
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Harlequin Opal
The rarest and most coveted opal play-of-color pattern, showing large, evenly spaced, angular mosaic patches of color.
gemstoneMintabie Opal
Precious opal from the Mintabie field in South Australia, known for hard, bright crystal opal and some dark-bodied stones.
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Virgin Valley Opal
Nevada's famous precious opal, including vivid black opal and opalized wood, renowned for brilliance but a notable tendency to craze.
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Opal
A hydrated silica gemstone famous for its shimmering play-of-color, ranging from white and black opal to fiery orange fire opal.
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Nevada Opal
Opal mined in Nevada, famous for fiery black precious opal and opalized wood from the Virgin Valley district.
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Australian Opal
Opal from Australia, the world's leading source of precious opal, ranging from white and crystal to prized black and boulder types.
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Rainbow Opal
Precious opal that displays a broad, vivid sweep of spectral colors, flashing the full rainbow as it is tilted in the light.
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Shell Opal
Fossil shells whose original material has been replaced by opal, preserving ancient marine forms in common or precious opal.
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Gold Opal
A golden-toned opal ranging from translucent common opal to precious stones flashing color against a warm yellow body.
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Lavender Opal
A pastel purple variety of common opal, valued for its gentle lilac body color rather than any play-of-color.
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Jelly Opal
A translucent, gelatinous-looking opal whose transparency gives floating, glowing play-of-color a watery, jelly-like appearance.
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Water Opal
A transparent, colorless opal that looks like water or jelly, sometimes flashing subtle play-of-color from within.
gemstonePink Opal
A soft pink common opal, most famously from Peru, valued for its gentle pastel color rather than play-of-color.
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Star Opal
Opal that displays a radiating, star-shaped pattern of play-of-color, a rare and prized internal structure.
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Welo Opal
Bright play-of-color opal from the Wollo Province of Ethiopia, mostly hydrophane and known for broad, vivid fire.
gemstoneIce Opal
A clear, glassy, near-colorless opal resembling ice, sometimes with subtle internal flashes of play-of-color.
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White Opal
The most common precious opal, with a pale milky body that shows softer pastel flashes of play-of-color throughout.
gemstoneFlame Opal
A glowing orange-to-red opal whose warm body color resembles flame; some stones add flashes of play-of-color.
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Blue Opal
A soft blue common opal, famously from Peru, valued for its serene sky-to-teal color rather than play-of-color.
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Spencer Opal
Precious opal from Spencer, Idaho, occurring in thin colorful seams that are typically cut into triplets.
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